Some machines, including many mobile machines, include a power system that supplies electricity to various electrical systems and components, such as starters, lighting components, relays, heating and cooling components, electronic control units, etc. In many of these machines, an alternator supplies the electricity to meet the electrical load created by these components. In some instances, a battery also provides electricity when a total electrical load is greater than what the alternator alone is capable of supplying at that time. For example, since alternator output may vary with a speed of the alternator, a battery may supplement power when the alternator is at low speeds. Use of the battery to supplement electricity in this manner, however, results in high battery drain and has a negative impact on battery life.
One attempt to reduce the use of a battery to supplement power is described in U.S. Pat. No. 8,140,240, which issued to Molen et al. on Mar. 20, 2012 (“the '240 patent”). The '240 patent describes a speed control system that adjusts the speed of a vehicle's engine to change an alternator's speed to meet a desired electrical output. In particular, an electronic controller calculates a current electrical load, and determines an appropriate alternator speed for the given conditions based on a relationship between the alternator's speed and load capability.
While the speed control system of the '240 patent may alleviate some strain on a battery in a power system, it may be less than optimal. In particular, use of the system may be complicated because it relies on user-input calibration values to account for variance between different machines. This may require additional effort to determine the calibration values for each machine prior to use of the system, and may not account for unknown variations that occur during operation. In particular, the system may not account for manufacturing variance and harness losses that may cause measured values to be different than actual conditions.
The present disclosure is directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.